Indicating circuit-controlling apparatus



June 10, 1930.

J. A. THOMMES 1,762,491 INDICATING CIRCUIT CONTROLLING APPARATUS FiledMag-ch 5, 1926 3 Sheets-$heet l I 262097251 c7512: 19. Win mas June 10,1930. J THOMMES 1,762,491

INDICATING CIRCUIT CONTROLLING APPARATUS Filed March 5, 1926 3Sheets-Sheet 2 J0//77 a4. 77701WI7/65 Patented June 10, 1930 UNITEDSTATES PATENT OFFICE JOHN A. THOMMES, OF CHICAGO, ILLINOIS, ASSIGNOR TOJAS. P. MARSH & COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION 01 ILLINOISINDICATING CIRCUIT-CONTROLLING APPARATUS Application filed March 5,1926. Serial No. 92,518.

My invention relates particularly to an indicating circuit controllerparticularly designed for use in connection with refrigeratingapparatus, compressors and the like where it is desired to maintainacontrol of the fluid pressure, but it may be used when ever foundapplicable. The invention has among its objects the production of adevice of the kind described that is simple, compact, efficient andsatisfactory. It has particularly as an object the production of asafety device that will indicate the conditions under which the same isworking, as well as control an electric circuit upon variation inconditions between desired limits. It has also among its objects theproduction of an instrument of the kind described in which thecontroller mechanism and the indicating mechanism are directly related,and whereby failure of either the indicating mechanism or circuitcontrolling mechanism to function will immediately be apparent. Manyother objects and advantages of the construction herein shown anddescribed will be obvious to those skilled in the art from thedisclosures herein given.

To this end my invention consists in the novel construction, arrangementand combination of parts herein shown and described, and moreparticularly pointed out in the claims.

In the drawings, wherein I have illustrated the preferred embodiment ofmy invention:

Fig. 1 is a face view of one type of instrument embodying the invention;

Fig. 2 is an enlarged view of the same, with the dial and front faceremoved;

Fig. 3 is a sectional view taken substantially on line 33 of' Fig. 1";

Fig. 4 is a sectional view taken substantially on line 44 of Fig. 2,with the dial and indicator in position;

Fig. 5 is an enlarged view of a portion of Fig. 2;

Fig. 6 is a similar View showing the parts in changed position;

Fig. 7 is a view taken substantially on line 77 of Fig. 5;

Fig. 8 is a face view of another embodiment of the invention with aportion of the dial removed to show the inner mechanism; and

' Fig. 9 is a similar view of another embodiment of the invention.

Referring to the drawings, 1 represents a shell or casing provided withtubular stem 2 for attachment to a'fluid pressure system and withelectrical conductors 3 extending to the desired electrical circuit inwhich the same is connected. Any type of circuit breaker may beemployed, that shown consisting so that the circuit through conductors 3is controlled by tilting or rocking the tube 4, as will be more fullyexplained in the operation of the device. In the instrument illustrated,the tilting of the tube is controlled by fluid pressure. A Bourdonspring 11 connected with the member 2 and open to the bore thereof, asindicated at 12, is arranged to actuate or control the movement of thetube 4. Variation in the pressure will cause a variation in the tubethrough the intermediate mechanism. Any suitable mechanism may beemployed for transmitting the movement of the Bourdon tube to the switchtube 4, that shown being merely illustrative and representing a typealready on the market with the exception of suitable connecting linksarranged between the Bourdon tube and the operating mechanism for theswitch 4; and between the -Bourdon tube and the indicator hand.

While I make no claim to the specific mechanism shown, the same may bedescribed in order that the operation of the instrument may beunderstood. As shown, 14 and .15 represent a frame secured to the casinby screws 16 or equivalent. The two frameliars 14 and 15 are maintainedin spaced relation by the spacers 17 and 18. The frame is provided withpins 19 and 26. The mercurycontaining tube 4 is mounted in or carried bya plate member 20 having depending arms 21 which firmly grip the tube 4.The carrier 20 is mounted on a plate 22 which is provided with theflange portion 23 pivotally mounted on a pin 19. As shown, the one endof 23 is bifurcated as at 24 and is ada ted to cooperate with the spacerpin 17 w ich limits its pivotal movement. The opposite end is formedwith cam faces 25. Mounted on the pin 26' is an arm 26 which carries apair of links 27 the lower endof which are pivotally secured to 26 asindlcated at 28. At the opposite end of links 27 -is -arranged a camroller 29 arranged to cooperate with the faces 25. A spring 30 securedat one end to the pin 30 on the frame engages the hook 31 at theopposite end which is shown pivotally secured to the links at 31'. Themovement of member 26 is limited by the engagement of the end 32 withthe pin 30 in one direction and by the engagement of the portion 23 withthe pin 18 at the opposite side. Member 26 is connected with the Bourdonspring 11 by a link 34 which is secured at the one end by a screw orbolt 35 to the member 26 which is formed with a slot 36 to permitadjustment. At the opposite end the same is connected to the Bourdonspring cars 39 b a pin 37 extending through the slot 38. gbviously theslot 38 may be formed in the other end of the link 34 if it is sodesired.

It will be particularly noted that the slot 38 and the link 34 permitsan initial movement of the Bourdon spring without tripping themechanism. The importance of this will be obvious from the descriptiongiven, and

in so far as I know this movement is new in apparatus of the kinddescribed Where as I am aware, the connection has been rigid, therebyrequiring a much more powerful or rigid Bourdon spring to be employed.It Wlll be obvious that the mechanism just described may be used alonewithout the indicating mechanism. Examination of the instrument initself did not disclose whether or not the switch was about to betripped in one direction or the other. I provide an indicator so that anengineer or attendant may at all times have a knowledge of the operativepressure in the system and whether the instrument is about to be trippedeither way.

As shown, 40 represents a dial provided with scale 41 thereon. Movableover the scale is an indicator 42 mounted on a rock shaft or pin 43.Secured to 43 is an arm 44 connected by a link 45 with the Bourdonspring 11, the link being. pivotaly connected at its ends to the pin 46on the arm and to the pin 37 previously described on the Bourdon spring.Obviously, as the Bourdon spring is actuated by the variation ofpressure in the system or by vacuum in the vacuum system, this movementwill be transmitted to the indicator, which will indicate on the scalethe conditions under which the Bourdon spring is 4 operating. The extentof movement of the s ring, as well as the particular readings on t escale, will, of course, depend on the particular instrument, this beingmade to suit the conditions under which the instrument is to beemployed.

With the preceding description in mind, the operation of the device maybe briefly explained as follows:

Movement of the-Bourdon spring will be indicated by movement of theindicator, the spring being designed for the particular pressure orfluid condition, and operation with the spring is apparent by referrinto the face of the instrument. Movement 0 the spring is also transmittedthrough the link 34 to the circuit controller mechanism. Inasmuch as itis desired to control the circuit controller between certain limits andnot continuously, the link is slotted as previously described so that atcertain oints in the expansion or contraction 0 the spring the member 26is rocked on its pivot 20.

Assuming that the parts are as shown in Fig. 5, it will be noted thatthe cam roller 29 is raised against one of the cam faces 25 andmaintaining the mercury tube 4 as shown in Fig. 2 so that the mercury isat the contact end of the tube and the contacts 5 are immersed therein,formin a circuit. If the Bourbon tube 11 expan s or tends to straightenout as indicated in Fig. 6, after an initial movement the same will movethe link 34 and member 26, drawing down upon the links 27 and cam roller29. This, how-v ever, has no effect on the tube carrier member 23, themovement of which-is limited by the pin 17 engaging one side of thebifurcated end of the member. Spring 30 maintains the roller 29 incontact with the cam face. After the roller passes the high spot of thecam and over to the other side, it tends to raise the end of 23, thespring moving the links 27 about the pivot 28. This causes the mercurytube 4 to be snapped .or flipped into the position shown in Fig. 6,throwing the mercur to the opposite end of the tube and away rom thecontacts 5, thereby breaking the circuit. If desired, manual means mayalso be employed to control the circuit controller. It will be noticedthat if the mercury tube 4 is reversed in its holder the operation willbe just the reverse of that described. The engineer, looking at the faceof the instrument, can tell by the indicator just what the workingconditions are in the system and whether the circuit controller is aboutto be trip ed or has just been tripped, etc. If desire a portion of thedial may be cut away, for illustration, as indicated at 40, so that thecircuit controller itself may be observed, although with the indicatingmechanism this is optional. The instrument itself, without someindicating mechanism, will of course,

disclose whether the circuit is Open, Q1 Closed,

. pumps, etc., and ma be instal but this does not disclose the immediatecondition of the system as is the case with my improved instrument. Insome instances may prefer to form the dial from transparent material sothat the circuit controller may be readily observed.

It may be mentioned that the slotted con nection of the link- 34 is avery desirable feature inasmuch as a more sensitive Bourdon tube may beemployed and there is no continual strain on the tubeinasmuch as thetripping is only after movement of the spring between its tri pingpositions.

Another em odiment of the instrument is shown in Fig. 8, in which acircuit controller similar to that described is employed, but in thiscase the instrument is rovided with an indicating mechanism whichpermits a wider range of travel of the indicator. As shown, 51represents the casing and 52 the Bourdon s rin 53 the conductors forminga part of t e circuit. In this case the s ring is connected by the link54 with t e controller mechanism, the link being slotted as shown at 55vto allow movement of the pin 56 in the slot except at the limits oftravel desired. I have shown a well-known type of movement in thisfigure, consisting of the frame 59 carrying a sector 60 which isconnected by link 57 with the Bourdon spring. Movement of the sector 60is transmitted through the pinion 61 to the inion shaft, carrying theindicator 58 which is movable over the dial plate 50. In this case, 62represents the usual lair spring employed in devices of this kind.

In the embodiment shown in 9, 63 represents the casing within which arearranged a pair of Bourdon tubes 64 and 65. one tube, as shown 65, isconnected through link 66 with the circuit controller from which extendsthe conductor 68, while the spring 64 is shown connected with link 67 tothe indicator mechanism arranged to actuate the indicator 69 and movethe same over the dial plate 70. In both of the constructions shown inFigs. 8 and 9, it is preferred to slot thev links 54 and 66 asindicated. This, however, is not uite so essential in the instrumentshown in Fig. 9, in which 'two\ Bourdon springs are employed, but it isnevertheless preferred.

The device is particularly simple and convenient, and has many uses. Itis particularly convenient for controlling compressors,

ed proximate to the machine to controlled or remote therefrom. Wheninstalled at a remote point,

the desirability of having the indicating mechanism is apparent. It willbe apparent from the preceding that the application of the indicatingmechanism is not limited to the specific circuit controller shown, butit is most desirable in connection with that particular type of circuitcontroller.

Having thus described my invention, it is ing a fluid pressure 0 obviousthat various immaterial modifications may be made in the same withoutdepartin from the spirit of my invention; ence do not wish to beunderstood as limiting myself to the exact form, construction,arrangement and combination of parts herein shown and described or usesmentioned.

What I claim as new and desire to secure by Letters Patent is:

1. In a device of the class described including a fluid pressure 0 rableelement and. in combination, a circuit reaker and indicating mechanismconnected for operation by sai element, links forming a connectionbetween said circuit breaker, indicating means and element, one end ofeach of said links being respectively connected with the indicator ancircuit breaker and one of said links having means afi'ording movementof said indicating means with respect to said circuit breaker.

2. In a device of the class described including a fluid pressureoperable element and in combination, a circuit breaker and indicatingmechanism connected for operation by sai element, links forming aconnection between said circuit breaker, indicating means andelement,-one end of each of said links bein respectively connected withthe indicator an circuit breaker and one of said links having meansaffording movement of said indicating means with respect to said circuitbreaker an permitting movement of said circuit breaker relatively tosaid indicator.

3. In a device of the class described includrable element and incombination, a circuit reaker and indicatin mechanism connected foroperation by sai element, links forming a connection between saidcircuit breaker, indicating means and element, one end of each of saidlinks being respectively connected with the indicator an circuit breakerand oneof said links having means afiordin movement of said circuitbreaker relative y to the indicator.

4. In a device of the class described having a fluid pressure operableelement in combination, a circuit breaker, indicatin mechanism signed myname.

JOHN A. THOMMES.

